The present invention is related to the field of television receivers and, more particularly, to the automatic alignment of such receivers in special applications such as video conferencing.
Conventional television receivers are designed and configured to optimize the display quality of video program material. For example, in the United States, televisions are typically optimized to display NTSC and/or S-video signals from sources such as television antennas, video cassette recorders, digital satellite television receivers and/or cable television sources. Under some circumstances, however, it is desirable to display other types of video images on a television receiver. For example, modem video conferencing systems often combine video signals (which may be formatted according to any of a variety of video signal transmission standards) with computer graphic signals (such as are used to display a variety of control buttons, etc.). Because the television is configured to optimize the display of conventional video signals, however, the resultant display of video conference image signals may be less than satisfactory.
To overcome some of these problems, computer-generated or other image signals are sometimes converted into conventional NTSC signals before being displayed. Although this arrangement may alleviate some of the problems associated with the display of such images on televisions, it does have some undesirable side effects. For example, because televisions are generally setup to overscan the picture, i.e., televisions typically do not display the entire image broadcast by the video source, and computer-generated images often use the entire visible raster (e.g., on a computer video monitor), the outer edges of the computer-generated image may be cut off when displayed on a television receiver. This may be compensated for through manual control inputs which may be used to adjust the picture size to accommodate the entire computer-generated image. The control inputs are generally provided by a user through manual input command paths within the television receiver, for example, hand-held remote control command input paths. Such alterations of the picture size will, however, have the drawback of effectively shrinking the display area of television receiver. Further, additional command and control inputs will be required when the television receiver is used to display conventional television video input signals (e.g., from a cable television source) to recover the original display size. Additionally, because the picture quality of a conventional television receiver degrades rapidly at the edges of the display, computer-generated material at the edges of the of the display (which may often be text, e.g., for a menu) will be displayed poorly.
In one embodiment, the present invention provides a method of aligning a television receiver. An alignment command is transmitted from a video conference application to the television receiver using an existing command path within the television receiver. The television receiver then reconfigures itself in accordance with the alignment command. Transmitting the alignment command may include formatting the command according to a protocol compatible with the existing command path within the television receiver. For example, a signal protocol compatible with a television remote control may be used. Further, the alignment command may be received at an input jack associated with the existing command path within said television receiver.
Configuring the television receiver may be accomplished by decoding the alignment command to obtain an alignment parameter for the television receiver. This may include accessing a table (e.g., a look-up table stored in a memory) to obtain the alignment parameter. The alignment parameter may then be used to produce a display alignment command for the television receiver.
In another embodiment, a television includes means for receiving an alignment command from a video conference source and means for configuring the television according to the alignment command. The receiving means may include a command input path adapted to receive the alignment command. This command input path may include a buffer for the alignment command.
The television""s means for configuring generally includes a programmable controller configured to provide a display alignment command to configure the television according to the alignment command. In addition, decoding means may be provided to decode the alignment command to obtain an alignment parameter. Such decoding means may include a look-up table (e.g., as stored in a memory) which includes the alignment parameter.
The television may also include a command path configured to provide command inputs to the video conference source and to the programmable controller. This command path may comprise a remote control input sensor adapted to receive command inputs from an associated remote control unit.
In yet a further embodiment, a command input path is provided. The command input path includes means for receiving a command signal from a video conference source indicating a television alignment parameter and means for configuring a television according to the alignment parameter. The means for receiving may comprise a control port configured to buffer the command signal. The means for configuring may comprise a programmable controller configured to obtain the alignment parameter from the alignment command. This may be accomplished using a look-up table (e.g., as stored in a memory) which includes the alignment parameter and which is coupled to the programmable controller.